Around 20:00 I opened a sequence for Abel 370 and clicked on “center now” and it quickly plate solved its way to the target.
When I try to go back to this target later in the night, this time around 23:15, I get an error message telling me Abel 370 is below the horizon, even though it is well overhead and near the meridian.
So “center now” works great early in the evening, but then gets very confused later in the evening when I try to use it exactly the same way.
Do you remember where the scope was pointing at 20:00?
If the object was “well overgeas” at 23:15, it should have been about 45 degrees up in the east at 20:00.
Hi Eric,
Yes 45 degrees above the eastern horizon is about right. Abell 370 is close to M77, for reference. And there was no issue with it slewing there with precision after a plate solve at 20:00.
But once it is past a certain time of the evening, what worked at 20:00 hours, “center now”, no longer works but gives me an error message that it can’t slew to target because it is below the horizon. The target is high in the sky, and I am just a few dozen pixels from being centered on it. But when I click “center now”, somehow it thinks the target is now below the horizon.
Dean
Here is a fresh example that just happened. I am done for the night now as I can’t get back on target after a focus run. At the start of the session, “center now” worked great. And now an hour or two later, “center now” gives me an error message and will not slew to target. Any help appreciated.
A look to “User Profil Manager” and under “Custom Horizon” and there check the values “Simple horizon” or “Use a custom horizon”. May be the values are too high.
Hi Helmut,
And thanks for the suggestion. I did check and it is set for a normal horizon, so that is not the problem. It is telling me a target that I had been on for hours that is now well overhead and near the meridian is below the horizon. I tried to plate solve to the target again last night using “center now”. It worked fine at the start of the session around 19:00. But when I tried “center now” around 20:30 after a focus run, it would tell me the target was below the horizon. Baffling. All my time zones and daylight savings time are correct in all applications. I don’t see where I have changed any settings, and the problem seemed to come out of the blue.
Dean
Hi Dean,
That is really a strange thing. I had very often a problem with the “Center” function. So I always make a plate solve before starting the “center now” and in most cases the result is ok.
Hello Helmut,
Plate solving has worked very well for me with SGP for years. And as is usual at the moment, last night it worked fine until about 20:00. After that it would tell me the target that I was on that was 50 degrees above the southern horizon was below the horizon and couldn’t be slewed to. Plate solving before doing anything else has no effect. It works fine until around 20:00, then it thinks the target that the telescope is on is below the horizon.
A typical night goes like this. Before 20:00, I have no issues at all with plate solving. It works well and fast as usual, and solves in seconds, and has no problem slewing to the target.
After about 20:00, I do an autofocus run without leaving the target. Because I am imaging with an Edge 9.25, my mirror can move slightly during focusing, taking me a few dozen pixels off the target. So after autofocusing, I always do a “center now” to move the few dozen pixels back to the target. And at that point I am told my target is below the horizon. Even though I am on the target at the moment, 50 degrees above the horizon, and just a few dozen pixels from where I want to be.
I will be tearing down in a few days and would sure like to solve this before I do, so that I am ready to image in two weeks at the next dark period. I was wondering if it could be something wrong in APCC, but it just updated to a new version last night and it changed nothing. This did happen after an SGP update, so I assume it is a problem with SGP. Maybe I will try going back a few versions in SGP tonight to see if it solves the issue. I don’t even know if I can do that without losing my settings in SGP.
Dean
Hello Dean
That’s really crazy! I’m working with SGP 4.4.1.1441. The plate solve works under ASTAP for slewing to target and for centering I choose Plate Solve3 - both are aktiv (and installed) with Control Panel - Plate Solve Chain. For your problem I have no solution - I had this issue “target is below horizon” because there was a too high value under “Cutom Horizon”.
Sorry, for my bad English and I hope you will find the error soon
Helmut
Thanks for the help Helmut, and your English is excellent!
I have this issue with the version you are using, as well as the lastest release, which is what I am running at the moment. I wonder if I can go to the version previous to 4.4.1.1441 without losing any settings? That would at least be a temporary solution for me. My solvers at the moment are ASTAP and for blind solving ANSVR. Before about 20:00, everything is solved almost instantly by ASTAP, and I never need the blind solver. And it then slews to the target as usual if I click “center now”. But after about 20:00, while it still solves the image, it somehow gets very confused as to where it actually is, and can’t slew to the target anymore because it thinks it is below the horizon. Really strange.
Dean